<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			.aaa{
				width: 300px;
				outline: 1px solid red;
			}
			.aaa .content{
				transition: all 2s ease 1s;
			}
			.aaa .hover{
				background: #ccc;
				
			}
			.aaa:hover .content{
				background: red;
			}
		</style>
	</head>
	<body>
		<div class="aaa">
			<div class="hover">鼠标移入</div>
			<div class="content">
				<p>11111111111111111111</p>
				<p>11111111111111111111</p>
				<p>11111111111111111111</p>
				<p>11111111111111111111</p>
				<p>11111111111111111111</p>
				<p>11111111111111111111</p>
			</div>
		</div>
	</body>
</html>
